quantum/audio/audio.c

   1 /* Copyright 2016 Jack Humbert
   2  *
   3  * This program is free software: you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation, either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16 #include <stdio.h>
  17 #include <string.h>
  18 //#include <math.h>
  19 #include <avr/pgmspace.h>
  20 #include <avr/interrupt.h>
  21 #include <avr/io.h>
  22 #include "print.h"
  23 #include "audio.h"
  24 #include "keymap.h"
  25
  26 #include "eeconfig.h"
  27
  28 #define CPU_PRESCALER 8
  29
  30 // -----------------------------------------------------------------------------
  31 // Timer Abstractions
  32 // -----------------------------------------------------------------------------
  33
  34 // TIMSK3 - Timer/Counter #3 Interrupt Mask Register
  35 // Turn on/off 3A interputs, stopping/enabling the ISR calls
  36 #ifdef C6_AUDIO
  37     #define ENABLE_AUDIO_COUNTER_3_ISR TIMSK3 |= _BV(OCIE3A)
  38     #define DISABLE_AUDIO_COUNTER_3_ISR TIMSK3 &= ~_BV(OCIE3A)
  39 #endif
  40
  41 #ifdef B5_AUDIO
  42     #define ENABLE_AUDIO_COUNTER_1_ISR TIMSK1 |= _BV(OCIE1A)
  43     #define DISABLE_AUDIO_COUNTER_1_ISR TIMSK1 &= ~_BV(OCIE1A)
  44 #endif
  45
  46 // TCCR3A: Timer/Counter #3 Control Register
  47 // Compare Output Mode (COM3An) = 0b00 = Normal port operation, OC3A disconnected from PC6
  48
  49 #ifdef C6_AUDIO
  50     #define ENABLE_AUDIO_COUNTER_3_OUTPUT TCCR3A |= _BV(COM3A1);
  51     #define DISABLE_AUDIO_COUNTER_3_OUTPUT TCCR3A &= ~(_BV(COM3A1) | _BV(COM3A0));
  52 #endif
  53
  54 #ifdef B5_AUDIO
  55     #define ENABLE_AUDIO_COUNTER_1_OUTPUT TCCR1A |= _BV(COM1A1);
  56     #define DISABLE_AUDIO_COUNTER_1_OUTPUT TCCR1A &= ~(_BV(COM1A1) | _BV(COM1A0));
  57 #endif
  58
  59 // Fast PWM Mode Controls
  60
  61 #ifdef C6_AUDIO
  62     #define TIMER_3_PERIOD     ICR3
  63     #define TIMER_3_DUTY_CYCLE OCR3A
  64 #endif
  65
  66 #ifdef B5_AUDIO
  67     #define TIMER_1_PERIOD     ICR1
  68     #define TIMER_1_DUTY_CYCLE OCR1A
  69 #endif
  70
  71
  72 // -----------------------------------------------------------------------------
  73
  74
  75 int voices = 0;
  76 int voice_place = 0;
  77 float frequency = 0;
  78 float frequency_alt = 0;
  79 int volume = 0;
  80 long position = 0;
  81
  82 float frequencies[8] = {0, 0, 0, 0, 0, 0, 0, 0};
  83 int volumes[8] = {0, 0, 0, 0, 0, 0, 0, 0};
  84 bool sliding = false;
  85
  86 float place = 0;
  87
  88 uint8_t * sample;
  89 uint16_t sample_length = 0;
  90
  91 bool     playing_notes = false;
  92 bool     playing_note = false;
  93 float    note_frequency = 0;
  94 float    note_length = 0;
  95 uint8_t  note_tempo = TEMPO_DEFAULT;
  96 float    note_timbre = TIMBRE_DEFAULT;
  97 uint16_t note_position = 0;
  98 float (* notes_pointer)[][2];
  99 uint16_t notes_count;
 100 bool     notes_repeat;
 101 float    notes_rest;
 102 bool     note_resting = false;
 103
 104 uint8_t current_note = 0;
 105 uint8_t rest_counter = 0;
 106
 107 #ifdef VIBRATO_ENABLE
 108 float vibrato_counter = 0;
 109 float vibrato_strength = .5;
 110 float vibrato_rate = 0.125;
 111 #endif
 112
 113 float polyphony_rate = 0;
 114
 115 static bool audio_initialized = false;
 116
 117 audio_config_t audio_config;
 118
 119 uint16_t envelope_index = 0;
 120 bool glissando = true;
 121
 122 void audio_init()
 123 {
 124
 125     // Check EEPROM
 126     if (!eeconfig_is_enabled())
 127     {
 128         eeconfig_init();
 129     }
 130     audio_config.raw = eeconfig_read_audio();
 131
 132     // Set port PC6 (OC3A and /OC4A) as output
 133
 134     #ifdef C6_AUDIO
 135         DDRC |= _BV(PORTC6);
 136     #else
 137         DDRC |= _BV(PORTC6);
 138         PORTC &= ~_BV(PORTC6);
 139     #endif
 140
 141     #ifdef B5_AUDIO
 142         DDRB |= _BV(PORTB5);
 143     #else
 144         DDRB |= _BV(PORTB5);
 145         PORTB &= ~_BV(PORTB5);
 146     #endif
 147
 148     #ifdef C6_AUDIO
 149         DISABLE_AUDIO_COUNTER_3_ISR;
 150     #endif
 151
 152     #ifdef B5_AUDIO
 153         DISABLE_AUDIO_COUNTER_1_ISR;
 154     #endif
 155
 156     // TCCR3A / TCCR3B: Timer/Counter #3 Control Registers
 157     // Compare Output Mode (COM3An) = 0b00 = Normal port operation, OC3A disconnected from PC6
 158     // Waveform Generation Mode (WGM3n) = 0b1110 = Fast PWM Mode 14 (Period = ICR3, Duty Cycle = OCR3A)
 159     // Clock Select (CS3n) = 0b010 = Clock / 8
 160
 161     #ifdef C6_AUDIO
 162         TCCR3A = (0 << COM3A1) | (0 << COM3A0) | (1 << WGM31) | (0 << WGM30);
 163         TCCR3B = (1 << WGM33)  | (1 << WGM32)  | (0 << CS32)  | (1 << CS31) | (0 << CS30);
 164     #endif
 165
 166     #ifdef B5_AUDIO
 167         TCCR1A = (0 << COM1A1) | (0 << COM1A0) | (1 << WGM11) | (0 << WGM10);
 168         TCCR1B = (1 << WGM13)  | (1 << WGM12)  | (0 << CS12)  | (1 << CS11) | (0 << CS10);
 169     #endif
 170
 171     audio_initialized = true;
 172 }
 173
 174 void stop_all_notes()
 175 {
 176     dprintf("audio stop all notes");
 177
 178     if (!audio_initialized) {
 179         audio_init();
 180     }
 181     voices = 0;
 182
 183
 184     #ifdef C6_AUDIO
 185         DISABLE_AUDIO_COUNTER_3_ISR;
 186         DISABLE_AUDIO_COUNTER_3_OUTPUT;
 187     #endif
 188
 189     #ifdef B5_AUDIO
 190         DISABLE_AUDIO_COUNTER_1_ISR;
 191         DISABLE_AUDIO_COUNTER_1_OUTPUT;
 192     #endif
 193
 194     playing_notes = false;
 195     playing_note = false;
 196     frequency = 0;
 197     frequency_alt = 0;
 198     volume = 0;
 199
 200     for (uint8_t i = 0; i < 8; i++)
 201     {
 202         frequencies[i] = 0;
 203         volumes[i] = 0;
 204     }
 205 }
 206
 207 void stop_note(float freq)
 208 {
 209     dprintf("audio stop note freq=%d", (int)freq);
 210
 211     if (playing_note) {
 212         if (!audio_initialized) {
 213             audio_init();
 214         }
 215         for (int i = 7; i >= 0; i--) {
 216             if (frequencies[i] == freq) {
 217                 frequencies[i] = 0;
 218                 volumes[i] = 0;
 219                 for (int j = i; (j < 7); j++) {
 220                     frequencies[j] = frequencies[j+1];
 221                     frequencies[j+1] = 0;
 222                     volumes[j] = volumes[j+1];
 223                     volumes[j+1] = 0;
 224                 }
 225                 break;
 226             }
 227         }
 228         voices--;
 229         if (voices < 0)
 230             voices = 0;
 231         if (voice_place >= voices) {
 232             voice_place = 0;
 233         }
 234         if (voices == 0) {
 235             #ifdef C6_AUDIO
 236                 DISABLE_AUDIO_COUNTER_3_ISR;
 237                 DISABLE_AUDIO_COUNTER_3_OUTPUT;
 238             #endif
 239             #ifdef B5_AUDIO
 240                 DISABLE_AUDIO_COUNTER_1_ISR;
 241                 DISABLE_AUDIO_COUNTER_1_OUTPUT;
 242             #endif
 243             frequency = 0;
 244             frequency_alt = 0;
 245             volume = 0;
 246             playing_note = false;
 247         }
 248     }
 249 }
 250
 251 #ifdef VIBRATO_ENABLE
 252
 253 float mod(float a, int b)
 254 {
 255     float r = fmod(a, b);
 256     return r < 0 ? r + b : r;
 257 }
 258
 259 float vibrato(float average_freq) {
 260     #ifdef VIBRATO_STRENGTH_ENABLE
 261         float vibrated_freq = average_freq * pow(vibrato_lut[(int)vibrato_counter], vibrato_strength);
 262     #else
 263         float vibrated_freq = average_freq * vibrato_lut[(int)vibrato_counter];
 264     #endif
 265     vibrato_counter = mod((vibrato_counter + vibrato_rate * (1.0 + 440.0/average_freq)), VIBRATO_LUT_LENGTH);
 266     return vibrated_freq;
 267 }
 268
 269 #endif
 270
 271 #ifdef C6_AUDIO
 272 ISR(TIMER3_COMPA_vect)
 273 {
 274     float freq, freq_alt = 0;
 275
 276     if (playing_note) {
 277         if (voices > 0) {
 278
 279             #ifdef B5_AUDIO
 280                 if (voices > 1) {
 281                     if (polyphony_rate == 0) {
 282                         if (glissando) {
 283                             if (frequency_alt != 0 && frequency_alt < frequencies[voices - 2] && frequency_alt < frequencies[voices - 2] * pow(2, -440/frequencies[voices - 2]/12/2)) {
 284                                 frequency_alt = frequency_alt * pow(2, 440/frequency_alt/12/2);
 285                             } else if (frequency_alt != 0 && frequency_alt > frequencies[voices - 2] && frequency_alt > frequencies[voices - 2] * pow(2, 440/frequencies[voices - 2]/12/2)) {
 286                                 frequency_alt = frequency_alt * pow(2, -440/frequency_alt/12/2);
 287                             } else {
 288                                 frequency_alt = frequencies[voices - 2];
 289                             }
 290                         } else {
 291                             frequency_alt = frequencies[voices - 2];
 292                         }
 293
 294                         #ifdef VIBRATO_ENABLE
 295                             if (vibrato_strength > 0) {
 296                                 freq_alt = vibrato(frequency_alt);
 297                             } else {
 298                                 freq_alt = frequency_alt;
 299                             }
 300                         #else
 301                             freq_alt = frequency_alt;
 302                         #endif
 303                     }
 304
 305                     if (envelope_index < 65535) {
 306                         envelope_index++;
 307                     }
 308
 309                     freq_alt = voice_envelope(freq_alt);
 310
 311                     if (freq_alt < 30.517578125) {
 312                         freq_alt = 30.52;
 313                     }
 314
 315                     TIMER_1_PERIOD = (uint16_t)(((float)F_CPU) / (freq_alt * CPU_PRESCALER));
 316                     TIMER_1_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq_alt * CPU_PRESCALER)) * note_timbre);
 317                 }
 318             #endif
 319
 320             if (polyphony_rate > 0) {
 321                 if (voices > 1) {
 322                     voice_place %= voices;
 323                     if (place++ > (frequencies[voice_place] / polyphony_rate / CPU_PRESCALER)) {
 324                         voice_place = (voice_place + 1) % voices;
 325                         place = 0.0;
 326                     }
 327                 }
 328
 329                 #ifdef VIBRATO_ENABLE
 330                     if (vibrato_strength > 0) {
 331                         freq = vibrato(frequencies[voice_place]);
 332                     } else {
 333                         freq = frequencies[voice_place];
 334                     }
 335                 #else
 336                     freq = frequencies[voice_place];
 337                 #endif
 338             } else {
 339                 if (glissando) {
 340                     if (frequency != 0 && frequency < frequencies[voices - 1] && frequency < frequencies[voices - 1] * pow(2, -440/frequencies[voices - 1]/12/2)) {
 341                         frequency = frequency * pow(2, 440/frequency/12/2);
 342                     } else if (frequency != 0 && frequency > frequencies[voices - 1] && frequency > frequencies[voices - 1] * pow(2, 440/frequencies[voices - 1]/12/2)) {
 343                         frequency = frequency * pow(2, -440/frequency/12/2);
 344                     } else {
 345                         frequency = frequencies[voices - 1];
 346                     }
 347                 } else {
 348                     frequency = frequencies[voices - 1];
 349                 }
 350
 351                 #ifdef VIBRATO_ENABLE
 352                     if (vibrato_strength > 0) {
 353                         freq = vibrato(frequency);
 354                     } else {
 355                         freq = frequency;
 356                     }
 357                 #else
 358                     freq = frequency;
 359                 #endif
 360             }
 361
 362             if (envelope_index < 65535) {
 363                 envelope_index++;
 364             }
 365
 366             freq = voice_envelope(freq);
 367
 368             if (freq < 30.517578125) {
 369                 freq = 30.52;
 370             }
 371
 372             TIMER_3_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
 373             TIMER_3_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
 374         }
 375     }
 376
 377     if (playing_notes) {
 378         if (note_frequency > 0) {
 379             #ifdef VIBRATO_ENABLE
 380                 if (vibrato_strength > 0) {
 381                     freq = vibrato(note_frequency);
 382                 } else {
 383                     freq = note_frequency;
 384                 }
 385             #else
 386                     freq = note_frequency;
 387             #endif
 388
 389             if (envelope_index < 65535) {
 390                 envelope_index++;
 391             }
 392             freq = voice_envelope(freq);
 393
 394             TIMER_3_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
 395             TIMER_3_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
 396         } else {
 397             TIMER_3_PERIOD = 0;
 398             TIMER_3_DUTY_CYCLE = 0;
 399         }
 400
 401         note_position++;
 402         bool end_of_note = false;
 403         if (TIMER_3_PERIOD > 0) {
 404             end_of_note = (note_position >= (note_length / TIMER_3_PERIOD * 0xFFFF));
 405         } else {
 406             end_of_note = (note_position >= (note_length * 0x7FF));
 407         }
 408
 409         if (end_of_note) {
 410             current_note++;
 411             if (current_note >= notes_count) {
 412                 if (notes_repeat) {
 413                     current_note = 0;
 414                 } else {
 415                     DISABLE_AUDIO_COUNTER_3_ISR;
 416                     DISABLE_AUDIO_COUNTER_3_OUTPUT;
 417                     playing_notes = false;
 418                     return;
 419                 }
 420             }
 421             if (!note_resting && (notes_rest > 0)) {
 422                 note_resting = true;
 423                 note_frequency = 0;
 424                 note_length = notes_rest;
 425                 current_note--;
 426             } else {
 427                 note_resting = false;
 428                 envelope_index = 0;
 429                 note_frequency = (*notes_pointer)[current_note][0];
 430                 note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100);
 431             }
 432
 433             note_position = 0;
 434         }
 435     }
 436
 437     if (!audio_config.enable) {
 438         playing_notes = false;
 439         playing_note = false;
 440     }
 441 }
 442 #endif
 443
 444 ISR(TIMER1_COMPA_vect)
 445 {
 446     #if defined(B5_AUDIO) && !defined(C6_AUDIO)
 447     float freq = 0;
 448
 449     if (playing_note) {
 450         if (voices > 0) {
 451             if (polyphony_rate > 0) {
 452                 if (voices > 1) {
 453                     voice_place %= voices;
 454                     if (place++ > (frequencies[voice_place] / polyphony_rate / CPU_PRESCALER)) {
 455                         voice_place = (voice_place + 1) % voices;
 456                         place = 0.0;
 457                     }
 458                 }
 459
 460                 #ifdef VIBRATO_ENABLE
 461                     if (vibrato_strength > 0) {
 462                         freq = vibrato(frequencies[voice_place]);
 463                     } else {
 464                         freq = frequencies[voice_place];
 465                     }
 466                 #else
 467                     freq = frequencies[voice_place];
 468                 #endif
 469             } else {
 470                 if (glissando) {
 471                     if (frequency != 0 && frequency < frequencies[voices - 1] && frequency < frequencies[voices - 1] * pow(2, -440/frequencies[voices - 1]/12/2)) {
 472                         frequency = frequency * pow(2, 440/frequency/12/2);
 473                     } else if (frequency != 0 && frequency > frequencies[voices - 1] && frequency > frequencies[voices - 1] * pow(2, 440/frequencies[voices - 1]/12/2)) {
 474                         frequency = frequency * pow(2, -440/frequency/12/2);
 475                     } else {
 476                         frequency = frequencies[voices - 1];
 477                     }
 478                 } else {
 479                     frequency = frequencies[voices - 1];
 480                 }
 481
 482                 #ifdef VIBRATO_ENABLE
 483                     if (vibrato_strength > 0) {
 484                         freq = vibrato(frequency);
 485                     } else {
 486                         freq = frequency;
 487                     }
 488                 #else
 489                     freq = frequency;
 490                 #endif
 491             }
 492
 493             if (envelope_index < 65535) {
 494                 envelope_index++;
 495             }
 496
 497             freq = voice_envelope(freq);
 498
 499             if (freq < 30.517578125) {
 500                 freq = 30.52;
 501             }
 502
 503             TIMER_1_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
 504             TIMER_1_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
 505         }
 506     }
 507
 508     if (playing_notes) {
 509         if (note_frequency > 0) {
 510             #ifdef VIBRATO_ENABLE
 511                 if (vibrato_strength > 0) {
 512                     freq = vibrato(note_frequency);
 513                 } else {
 514                     freq = note_frequency;
 515                 }
 516             #else
 517                     freq = note_frequency;
 518             #endif
 519
 520             if (envelope_index < 65535) {
 521                 envelope_index++;
 522             }
 523             freq = voice_envelope(freq);
 524
 525             TIMER_1_PERIOD = (uint16_t)(((float)F_CPU) / (freq * CPU_PRESCALER));
 526             TIMER_1_DUTY_CYCLE = (uint16_t)((((float)F_CPU) / (freq * CPU_PRESCALER)) * note_timbre);
 527         } else {
 528             TIMER_1_PERIOD = 0;
 529             TIMER_1_DUTY_CYCLE = 0;
 530         }
 531
 532         note_position++;
 533         bool end_of_note = false;
 534         if (TIMER_1_PERIOD > 0) {
 535             end_of_note = (note_position >= (note_length / TIMER_1_PERIOD * 0xFFFF));
 536         } else {
 537             end_of_note = (note_position >= (note_length * 0x7FF));
 538         }
 539
 540         if (end_of_note) {
 541             current_note++;
 542             if (current_note >= notes_count) {
 543                 if (notes_repeat) {
 544                     current_note = 0;
 545                 } else {
 546                     DISABLE_AUDIO_COUNTER_1_ISR;
 547                     DISABLE_AUDIO_COUNTER_1_OUTPUT;
 548                     playing_notes = false;
 549                     return;
 550                 }
 551             }
 552             if (!note_resting && (notes_rest > 0)) {
 553                 note_resting = true;
 554                 note_frequency = 0;
 555                 note_length = notes_rest;
 556                 current_note--;
 557             } else {
 558                 note_resting = false;
 559                 envelope_index = 0;
 560                 note_frequency = (*notes_pointer)[current_note][0];
 561                 note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100);
 562             }
 563
 564             note_position = 0;
 565         }
 566     }
 567
 568     if (!audio_config.enable) {
 569         playing_notes = false;
 570         playing_note = false;
 571     }
 572 #endif
 573 }
 574
 575 void play_note(float freq, int vol) {
 576
 577     dprintf("audio play note freq=%d vol=%d", (int)freq, vol);
 578
 579     if (!audio_initialized) {
 580         audio_init();
 581     }
 582
 583     if (audio_config.enable && voices < 8) {
 584         #ifdef C6_AUDIO
 585             DISABLE_AUDIO_COUNTER_3_ISR;
 586         #endif
 587         #ifdef B5_AUDIO
 588             DISABLE_AUDIO_COUNTER_1_ISR;
 589         #endif
 590
 591         // Cancel notes if notes are playing
 592         if (playing_notes)
 593             stop_all_notes();
 594
 595         playing_note = true;
 596
 597         envelope_index = 0;
 598
 599         if (freq > 0) {
 600             frequencies[voices] = freq;
 601             volumes[voices] = vol;
 602             voices++;
 603         }
 604
 605         #ifdef C6_AUDIO
 606             ENABLE_AUDIO_COUNTER_3_ISR;
 607             ENABLE_AUDIO_COUNTER_3_OUTPUT;
 608         #endif
 609         #ifdef B5_AUDIO
 610             #ifdef C6_AUDIO
 611             if (voices > 1) {
 612                 ENABLE_AUDIO_COUNTER_1_ISR;
 613                 ENABLE_AUDIO_COUNTER_1_OUTPUT;
 614             }
 615             #else
 616             ENABLE_AUDIO_COUNTER_1_ISR;
 617             ENABLE_AUDIO_COUNTER_1_OUTPUT;
 618             #endif
 619         #endif
 620     }
 621
 622 }
 623
 624 void play_notes(float (*np)[][2], uint16_t n_count, bool n_repeat, float n_rest)
 625 {
 626
 627     if (!audio_initialized) {
 628         audio_init();
 629     }
 630
 631     if (audio_config.enable) {
 632
 633         #ifdef C6_AUDIO
 634             DISABLE_AUDIO_COUNTER_3_ISR;
 635         #endif
 636         #ifdef B5_AUDIO
 637             DISABLE_AUDIO_COUNTER_1_ISR;
 638         #endif
 639
 640         // Cancel note if a note is playing
 641         if (playing_note)
 642             stop_all_notes();
 643
 644         playing_notes = true;
 645
 646         notes_pointer = np;
 647         notes_count = n_count;
 648         notes_repeat = n_repeat;
 649         notes_rest = n_rest;
 650
 651         place = 0;
 652         current_note = 0;
 653
 654         note_frequency = (*notes_pointer)[current_note][0];
 655         note_length = ((*notes_pointer)[current_note][1] / 4) * (((float)note_tempo) / 100);
 656         note_position = 0;
 657
 658
 659         #ifdef C6_AUDIO
 660             ENABLE_AUDIO_COUNTER_3_ISR;
 661             ENABLE_AUDIO_COUNTER_3_OUTPUT;
 662         #endif
 663         #ifdef B5_AUDIO
 664             #ifndef C6_AUDIO
 665             ENABLE_AUDIO_COUNTER_1_ISR;
 666             ENABLE_AUDIO_COUNTER_1_OUTPUT;
 667             #endif
 668         #endif
 669     }
 670
 671 }
 672
 673 bool is_playing_notes(void) {
 674     return playing_notes;
 675 }
 676
 677 bool is_audio_on(void) {
 678     return (audio_config.enable != 0);
 679 }
 680
 681 void audio_toggle(void) {
 682     audio_config.enable ^= 1;
 683     eeconfig_update_audio(audio_config.raw);
 684     if (audio_config.enable)
 685         audio_on_user();
 686 }
 687
 688 void audio_on(void) {
 689     audio_config.enable = 1;
 690     eeconfig_update_audio(audio_config.raw);
 691     audio_on_user();
 692 }
 693
 694 void audio_off(void) {
 695     audio_config.enable = 0;
 696     eeconfig_update_audio(audio_config.raw);
 697 }
 698
 699 #ifdef VIBRATO_ENABLE
 700
 701 // Vibrato rate functions
 702
 703 void set_vibrato_rate(float rate) {
 704     vibrato_rate = rate;
 705 }
 706
 707 void increase_vibrato_rate(float change) {
 708     vibrato_rate *= change;
 709 }
 710
 711 void decrease_vibrato_rate(float change) {
 712     vibrato_rate /= change;
 713 }
 714
 715 #ifdef VIBRATO_STRENGTH_ENABLE
 716
 717 void set_vibrato_strength(float strength) {
 718     vibrato_strength = strength;
 719 }
 720
 721 void increase_vibrato_strength(float change) {
 722     vibrato_strength *= change;
 723 }
 724
 725 void decrease_vibrato_strength(float change) {
 726     vibrato_strength /= change;
 727 }
 728
 729 #endif  /* VIBRATO_STRENGTH_ENABLE */
 730
 731 #endif /* VIBRATO_ENABLE */
 732
 733 // Polyphony functions
 734
 735 void set_polyphony_rate(float rate) {
 736     polyphony_rate = rate;
 737 }
 738
 739 void enable_polyphony() {
 740     polyphony_rate = 5;
 741 }
 742
 743 void disable_polyphony() {
 744     polyphony_rate = 0;
 745 }
 746
 747 void increase_polyphony_rate(float change) {
 748     polyphony_rate *= change;
 749 }
 750
 751 void decrease_polyphony_rate(float change) {
 752     polyphony_rate /= change;
 753 }
 754
 755 // Timbre function
 756
 757 void set_timbre(float timbre) {
 758     note_timbre = timbre;
 759 }
 760
 761 // Tempo functions
 762
 763 void set_tempo(uint8_t tempo) {
 764     note_tempo = tempo;
 765 }
 766
 767 void decrease_tempo(uint8_t tempo_change) {
 768     note_tempo += tempo_change;
 769 }
 770
 771 void increase_tempo(uint8_t tempo_change) {
 772     if (note_tempo - tempo_change < 10) {
 773         note_tempo = 10;
 774     } else {
 775         note_tempo -= tempo_change;
 776     }
 777 }